Vacuum valve



Aug. 9, 1938. B. c; GARDNER VACUUM VALVE Filed Aug. 18, 1936 UNITED a zaeic VACUUM VALVE Be 0. Gardner,

1: l 1; eiphla, Pa", assignor to Farnsworth Television incorporated, San Francisco; Calif-, a corporatlonot California Application August 1t, 1936, Serial No. 96,611

2 Glalms.

This invention relates to apparatus for treating tubes or glassbulbs wlth'gas, and-more particularly to eflicient means for controlling the,'

i. e., the vacuum producing apparatus must be inoperative when the gas supply is efiective, and vice versa. 'The effective valves heretofore used have caused considerable annoyance due to the fact that they are usually of the ground glass stopcock variety which must be packed with grease at frequent intervals to maintain their eiiectiveness and to the fact that such grease leaks into the filling system and the vapors therefrom which enter the tube are subsequently detrimental to operation and life.

It is the principal object of my invention to provide an apparatus of the above indicated character .which is completely sealed from the atmosphere without employment of grease packings or the like.

It is a further object to provide a valve for use in such'an apparatus the moving parts of which are entirely sealed within'the evacuating system.

Further objects and advantages will become "clear to those skilled in the art upon reference to the following specificationin which reference is made to the accompanying drawing of a pre- I ierred embodiment of my invention and in which:

Figure 1 is an elevational'view, partially in section, indicating schematically the arrangement of the components of my vacuum valve.

Figure 2 is a sectional view of an alternative form of the electric valve component of Figure 1.

Figure 1 illustrates a filling and evacuating apparatus comprising a hollow glass conduit I having connected thereto a source ofhigh vacuum such as a mercury vacuum pump 2 and a source of filling gas such as a tank 3. The tube t to be evacuated and filled is fused to the conduit during theevacuation and filling. Interposed in ahorizontal section-of the conduit I is a liquid air trap 6. g

The filling gas from tank 3 is admitted to conduit I under control of a difl'usion valve 1, which in the form illustrated comprises a vertically disposed cylinder 8 containing mercury or the like. Gas supply conduit 9 terminates within the body of mercury and the latter is prevented from entering the conduit by a porcelain filter disk ill which'closes the upper end of conduit 9. Disposed for reciprocation in guide it in cylinder 8 is a second conduit section it similarly provided with a porcelain filter disk closure It, which also underlies the surface of the mercury and is juxtaposed to disk ill.

The section it may be looped as at M so that the end 83 thereof may be reciprocated up and down. It is a property" of the procelain filter disks that they will not pass mercury but will pass a gas. By forcing disks ill and i3 into contact, a free path is provided for the gas to pass into conduit l.

Between the point of connection of the gas supply to conduit I and vacuum pump 2, the conduit is provided with an interposed electric valve it which preferably comprises a valve closure plate it overlying the valve seat H at the end of V the vertically disposed section 98 of the conduit. Plate i6 is carried by a float llL'which is preferably a ring of iron, being secured thereto by vertically disposed legs 20. A sealed-in valve and float chamber is formed by a glass 7, envelope 2| received over the respective ends of the conduit l and. fused thereto as at the ring seals 22. As illustrated, the conduit section l8 projects into the envelope so as to form therewith anannular well for the reception of a body of mercury 23 or the like upon which fioat l9 rests.

Suitable guide rods 20 secured to valve plate It to slide within the conduit l8 insure proper positioning of the valve.

In order to actuate the valve closure l6 into closed position, a solenoid 24 is suitably disposed about the envelope and connected through a suitable switch 25 to a battery 26. A similar solenoid 21 may be provided for the purpose of releasing the valve to open position if the buoyancy of the mercury be insuflicient for the purpose;

In operation, a tube 4 to be evacuated is sealed to conduit l as indicated, the valves 1 and I5 preferably remaining closed during this -step.- Valve I5 is then opened and all gas is exhausted from the tube 3 and conduit I. Valve i5 is then-closed by closing switch 25, and gas admitted to tube 3 under control of valve 1. The tube is then sealed oil.

It will be appreciated that by applicant's construction the interior of the tube evacuating system is completely sealed from the atmosphere and no grease packings are necessary since no mechanlcal connection is required between the valve closure l6 and the solenoid operating means exterior of the envelope 2|.

In Figure 2, I have shown an alternative form for tile construction of the electric valve l5 of Figure 1. Upon float i9 is supported a cylinder 29 terminated at its upper end by plate 3Q. Ports 3| disposed through the cylinder walls provide an air passage when the float i9 is raised by actuating solenoid 21. When solenoid 24 is actuated ring His drawn downward, and the ports are closed by the mercury pool 23. I

Having described and'illustrated a preferred embodiment of my invention in a manner to enable those skilled in the art to make and use the same, it will be apparent that various modifications thereof may be resorted to without departing from its teachings. It is accordingly to be understood that I consider myself entitled to all such modifications and variations as properly lie within the scope of the following claims.

I claim as my invention:

1. A valve structure comprising a glass housing, a glass conduit sealed to said housing and projecting therewithin, a second glass conduit connected to said housing, a body of mercury within said housing, a float of magnetic material resting on said mercury body, a valve closure carried by said float for movement into and out of seating relation to a terminal end of said conduit, guide means secured to said float and disposed to slide within said conduit, and means including a solenoid surrounding said housing for actuating said valve.

2. A valve structure comprising a glass housing, a glass conduit sealed to said housing and projecting therewithin, a second glass conduit connected to said housing, a body of mercury within said housing, a float of magnetic material resting on said mercury body, a valve closure carried by said float and maintained by flotation away from a terminal end of said conduit, a solenoid positioned around said housing and below said float to close said valve when energized, and a second and similar solenoid positioned above said float to open said valve when energized.

BERNARD C. GARDNER. 

